JPH08592Y2 - Combustion device for flame-retardant fuel - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention is a combustion for a flame-retardant fuel used for burning a flame-retardant fuel that is hard to burn, such as one having a high water content or fine coke. Regarding the device.

(Prior art) For example, a substance containing a large amount of water such as lime and water slurry, aoko, okara, sludge, industrial waste, etc. generated in a lake or volatile matter such as fine coke. Powders and the like that do not contain are difficult to burn and are referred to as flame-retardant fuels (hereinafter, may be abbreviated as "fuel-reduced fuels"). Among these difficult fuels, those with a high water content have a small calorific value, poor ignitability, and low flame temperature. Those with a low volatile content have poor ignitability and a slow burning rate.

Even when such a difficult fuel is injected from the injection nozzle, a zone called a so-called black skirt where a flame is not partially formed is generated, and incomplete combustion often occurs.

Therefore, in the conventional combustion device, a burner is provided near the injection nozzle for injecting the fuel in order to stably form the flame.

FIG. 4 is a partially cutaway plan view showing an example of a conventional combustion device. The combustion apparatus shown here is provided with an injection nozzle 2 for injecting a difficult fuel at an end of a combustion furnace 1, and a burner nozzle 3 for injecting a flame toward the difficult fuel injected from the injection nozzle 2 is injected by the injection nozzle 2. It is provided near the nozzle 2.

In the figure, reference numeral "4" is a pilot burner, "5" is a viewing window, and "6" is a fuel inlet.

(Problems to be solved by the invention) However, in this combustion device 7, since the injection nozzle 2 and the burner nozzle 3 are close to each other, the flame injected from the burner nozzle 3 hits the fuel from the injection nozzle 2 while it does not grow sufficiently. It will be. The result is that the flame grown in the high temperature state does not hit the difficult fuel, but the fuel is burned in the lower temperature flame.

Therefore, the flame that enters the combustion furnace 1 from the crater 8 becomes a lift flame, and the fuel is not sufficiently burned. In order to prevent lift flame, if the flow velocity of fuel is low, the amount of combustion processing will be small and quick processing will not be possible, and if the flow velocity of fuel is increased, the lift flame formed as described above will blow off. Will be done.

The inventors of the present invention have focused their attention on the above-mentioned problems and as a result of diligent research, in order to completely burn even a difficult fuel, in order to sufficiently grow the flame of the burner nozzle for ignition, it is necessary to increase the time. The inventors have completed the present invention by paying attention to the fact that the flame can be formed with a sufficient space and the difficult fuel can be ignited by the flame at the high temperature to burn the fuel more reliably.

The present invention has various drawbacks associated with the above-mentioned conventional techniques,
It is an object of the present invention to solve the problems and to provide a difficult-fuel combustion device that can burn a predetermined amount of fuel quickly and reliably.

(Means for Solving the Problems) In order to achieve such an object, a combustion device for a flame-retardant fuel according to the present invention includes an injection nozzle for injecting a flame-retardant fuel into a combustion furnace, and the flame-retardant fuel. In a combustion device for a flame-retardant fuel having a burner nozzle that blows out a flame toward, a predetermined passage length and diameter are formed between the injection nozzle and the crater of the combustion furnace, and the periphery is made of a refractory material. A preheating space for preheating the enclosed flame-retardant fuel, and a flame formed between the preheating space and the tip of the injection port of the burner nozzle, which is blown out from the burner nozzle, is substantially completely combusted to make the preheating space flame-retardant. A flame growth space having a passage length and a diameter set so as to hit the fuel and surrounded by a refractory material, and an axis of the flame growth space intersects with the axis of the preheating space at an acute angle. It is characterized by having done.

Further, the crater is characterized in that an air nozzle for injecting secondary air is installed near the crater.

(Operation) In the present invention configured as described above, after the ignition flame blown out from the burner nozzle is sufficiently grown in the flame growth space to form a flame of substantially complete high temperature, this is injected from the injection nozzle to the preheating space. Since the fuel is ignited by colliding with or in contact with the generated difficult fuel, a flame in a more easily combustible state hits the difficult fuel, and even a difficult fuel having poor ignitability can be quickly and reliably burned.

Moreover, if an air nozzle that injects secondary air is installed near the crater, the secondary air can reliably burn the difficult fuel that is easily combustible.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall schematic explanatory view showing one embodiment of a flame-retardant fuel combustion apparatus according to the present invention, FIG. 2 is an enlarged cross-sectional view showing an essential part of FIG. 1, and FIG. It is explanatory drawing which shows the temperature state in a furnace.

In FIG. 1, a flame-retardant fuel combustion device 10 is a combustion furnace.
Injection nozzle 12 for injecting difficult fuel into the combustion furnace 11 at the end of 11
And a burner nozzle 13 for blowing a flame toward the difficult fuel.

The injection nozzle 12 is provided with a fuel supply unit 14 composed of a pump for supplying difficult fuel, preferably a snake pump or the like, to the conduit P1.
And the burner nozzle 13 is connected to the tank.
A pipe P2 for feeding the fuel stored in 15 such as kerosene by a pump 16 is connected.

The air to the injection nozzle 12 is introduced from the compressor 17 through the conduit P3, and the burner nozzle 13 has a blower 18
Combustion air from is introduced via conduit P4.

In FIG. 1, reference numeral "19" is a chimney and "M" is a motor.

Particularly, in this embodiment, as shown in FIG. 2, a preheating space 23 is formed between the injection nozzle 12 and the crater 20 of the combustion furnace 11.

The preheating space 23 is a space in which a difficult fuel is burned before being injected into the combustion furnace 11. Since the difficult fuel is a slurry of coal and water, a material containing a large amount of water such as Aoko produced in a lake, or a powder containing almost no volatile matter such as fine coke, It is difficult to instantly bring the ignition temperature to complete combustion. Therefore, in this embodiment, the preheating space 23 has a predetermined passage length L1 and a caliber D1 in order to increase the temperature of the difficult fuel temporally and spatially to the ignition temperature. The temperature of the fuel is raised while passing through the preheating space 23, so that the difficult fuel can be surely combusted when it reaches the combustion furnace 11.

The preheating space 23 is surrounded by the refractory material 21,
Further, the periphery of the refractory material 21 is covered with a heat insulating material 22.

On the other hand, on the side of the burner nozzle 13 as well, between the tip of the injection port 24 of the burner nozzle 13 and the preheating space 23, the flame blown out from the burner nozzle 13 is almost completely combusted to preheat the space.
23 has a passage length L2 and a diameter D2 that are set to collide with or come into contact with the difficult fuel 23, and the periphery is surrounded by a refractory material 21, and the periphery of the refractory material 21 is covered with a heat insulating material 22. A flame growth space 25 is formed.

The flame growth space 25 is provided to substantially completely burn the flame injected from the burner nozzle 13 to form a high temperature flame, and also in this case, a predetermined amount of fuel is temporally and spatially. With sufficient margin, it is designed to burn so as to form a nearly complete flame.

The term "substantially complete combustion" means that the combustion state is about 70% or more, and does not necessarily have to be 100%.

And the extension of the axis of the flame growth space 25 is the preheating space 23.
It intersects with the axis line at a predetermined angle θ. The crossing angle θ may be any angle as long as it can be set so that the grown flame collides with or contacts the difficult fuel. Further, the intersection of the axis of the flame growth space 25 and the axis of the preheating space 23 does not necessarily have to be present in the preheating space 23 up to the crater 20, and the intersections are arranged close to each other in parallel in the combustion furnace or It may be generated externally.

Further, an air nozzle 26 for injecting secondary air to the ignited difficult fuel is provided near the crater 20. Combustion air from the blower 18 is introduced into the air nozzle 26 via a conduit P5 branched from a conduit P4, and is injected from an injection port 27 so as to surround a flame of difficult fuel.

 Next, the operation of the above embodiment will be described.

When a power source (not shown) is turned on, first, the pump 16 and the blower 18 are operated, the kerosene and the combustion air are injected from the burner nozzle 13 into the flame growth space 25, and are ignited by an igniter (not shown) to form a flame.

This flame grows in the flame growth space 25. The flame growth space 25 has a predetermined axial length L1 and caliber D1, so the flame from the burner nozzle 13 is sufficiently combined with the surrounding air to be substantially completely combusted, and at a high temperature. A flame will be formed. The flame formed by the almost complete combustion has a high temperature like the A zone shown in FIG.

Next, the compressor 17 and the fuel supply unit 14 are operated to inject the difficult fuel from the injection nozzle 12 into the preheating space 23. Since the high-temperature flame grown in the flame growth space 25 intersects with the flow of the difficult fuel, the difficult fuel collides with the flame at a position where the flame is injected from the injection nozzle 12 for a predetermined length. Contact. As a result, the refractory fuel receives heat from the flame and its moisture evaporates and is heated.

Incidentally, the crossing angle θ is small, and the flame and the flame-retardant fuel flow may be in a parallel flow state, but in this case, if the flame growth space 25 and the preheating space 23 are arranged close to each other to some extent, the flame There is no problem because the flow of the difficult fuel collides with or comes into contact.

In the B zone in this state, the temperature drops as shown in FIG. However, the amount of the difficult fuel and the amount of kerosene are adjusted so that this temperature decrease does not fall below the ignition temperature of the difficult fuel, so that the injected difficult fuel is in an ignitable state or Ignition state.

The flame-retardant fuel thus ignited reaches the vicinity of the crater 20, but the crater 20 has an air nozzle 26 for injecting secondary air from the injection port 27. It receives fresh oxygen supplementation by air and burns more reliably, enters the C zone of the combustion furnace 11, and is completely burned.
As shown in FIG. 3, the temperature rises again, and even if the fuel is difficult, it will be combusted reliably.

According to the experiment, the passage length L1 of the preheating space 23 is 1200 mm, the diameter D1 is 600 mm, and the passage length L2 of the flame growth space 25 is 900 m.
m, diameter D2 is 450 mm, cross angle θ between preheating space 23 and flame growth space 25 is 30 degrees, and when kerosene is supplied at 35 to 70 kg / hour, it contains 80% moisture which is a difficult fuel. Aoko, 35
It was found that almost complete combustion can be achieved even when supplied at 0 kg / hour.

The present invention is not limited to the above-described embodiment, and the fuel guided to the burner nozzle 13 is not limited to kerosene but may be gas fuel.

(Effect of the Invention) As described above, according to the present invention, the flame blown from the burner nozzle is made almost perfect in the flame growth space, and the flame is collided with the difficult fuel injected from the injection nozzle into the preheating space. Since they are brought into contact with each other to make them more flammable, even a difficult fuel having a poor ignitability can be burned quickly and reliably.

Moreover, since the air nozzle for injecting the secondary air is installed in the vicinity of the crater, the combustion can be made more complete by the secondary air.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing the whole combustion apparatus for a flame-retardant fuel according to the present invention, FIG. 2 is an enlarged sectional view showing an essential part of FIG. 1, and FIG. 3 is a state of flame. FIG. 4 is a sectional view showing an example of a conventional combustion device. 11 ... Combustion furnace, 12 ... Injection nozzle, 13 ... Burner nozzle, 20 ... Vent, 21 ... Refractory material, 23 ... Preheating space, 24 ...
… Injection port, 25 …… Flame growth space, 26 …… Air nozzle, D
1, D2 …… caliber, L1, L2 …… passage length, θ …… intersection angle.

Claims (2)

[Scope of utility model registration request] 1. A flame-retardant fuel having an injection nozzle (12) for injecting a flame-retardant fuel into a combustion furnace (11) and a burner nozzle (13) for blowing a flame toward the flame-retardant fuel. In the combustion device, a refractory material is formed between the injection nozzle (12) and the crater (20) of the combustion furnace (11) and has a predetermined passage length (L1) and caliber (D1). A preheating space (23) for preheating the flame-retardant fuel surrounded by (21), and a burner nozzle (13) formed between the preheating space (23) and the tip of (24) at the injection port of the burner nozzle (13). ), The flame blown out of the preheating space (23)
Passage length (L2) set to hit the flame-retardant fuel of
And a caliber (D2) and a flame growth space (25) surrounded by a refractory material (21). The axis of the flame growth space (25) is the axis of the preheating space (23). Combustion device for flame-retardant fuel, characterized in that it intersects at an acute angle. 2. The combustion device for flame-retardant fuel according to claim 1, wherein an air nozzle (26) for injecting secondary air is installed in the vicinity of the crater (20).